1. Field of the Invention
This invention relates to a display system for use when display data output by a computer differs in resolution from a liquid crystal display screen, which is to display the display data, used as a display for a personal computer, etc.
2. Description of the Related Art
A conventional liquid crystal display receives an interface signal containing display data and a timing signal output by a computer, converts the interface signal into a drive signal for the liquid crystal display, and feeds the drive signal into a liquid crystal drive means. The liquid crystal drive means converts the display data contained in the drive signal into a liquid crystal drive voltage corresponding to the display data and outputs the voltage to a liquid crystal panel. When receiving the liquid crystal drive voltage, the liquid crystal panel displays an image. If the input interface signal differs from the liquid crystal panel in resolution, for example, if the resolution of the input interface signal is larger than that of the liquid crystal panel, a part of the display data contained in the input interface signal is deleted to match the resolution of the interface signal with that of the liquid crystal panel, as described in Japanese Patent Laid-Open No. 57-115593. In the conventional example, the display object is limited to characters and space dots around a character are deleted for each kind of character. The part to be deleted needs to be specified for each kind of character.
The conventional example applies to characters and is not intended for displaying data other than characters.
It is therefore an object of the invention to provide a liquid crystal display system which can accept an interface signal having a resolution different from that of the liquid crystal display for displaying the display data contained in the interface signal regardless of the type of display data.
To this end, according to one aspect of the invention, there is provided a method of converting first display data in a raster scan format having a first resolution received from an external system into second display data for a liquid crystal display having a second resolution different from the first resolution, the method comprising the steps of:
a) generating data for n vertical or horizontal lines based on specific m vertical or horizontal lines contiguous to each other of the first display data, where m is an integer of two or greater and n is an integer less than m;
b) repeating at least one of the following steps c) and d) as many times as required in sequence at different positions on a screen of the liquid crystal display;
c) replacing k (n less than kxe2x89xa6m) lines of the m vertical or horizontal lines with the n vertical or horizontal lines; and
d) adding the n vertical or horizontal lines to the m vertical or horizontal lines.
The data conversion means converts display data received from a personal computer or the like into display data using gray scale data so that it matches the resolution of the liquid crystal display. Thus, even display data output by the personal computer or the like assuming an output device having resolution different from that of the liquid crystal display can be displayed on the liquid crystal display.
According to another aspect of the invention, there is provided a method of converting first display data in a raster scan format having a first horizontal resolution received from an external system into second display data for a liquid crystal display having a second horizontal resolution smaller than the first horizontal resolution, the method comprising the steps of:
a) virtually dividing a set of M contiguous dots on a horizontal line into N equal partitions, where M is an integer of three or greater and N is an integer of two or more, less than M;
b) repeating, N times with respect to the N equal partitions, a weighted addition of data values of dots contained in one partition, depending upon what percentage of the partition is occupied by each dot in the partition;
c) replacing the M dots with n dots which have the data values of the N partitions resulting from the weighted additions in step b);
d) repeating steps a) to c) for different sets of M contiguous dots in sequence at least in a part of one horizontal line; and
e) repeating step d) for different horizontal lines in sequence.
According to still another aspect of the invention, there is provided a method of converting first display data in a raster scan format having first horizontal resolution received from an external system into second display data for a liquid crystal display having second horizontal resolution larger than the first horizontal resolution, the method comprising the steps of:
a) virtually dividing a set of M contiguous dots on a horizontal line into N equal partitions, where M is an integer of two or greater and N is an integer of three or more which is greater than M;
b) repeating, N times with respect to the N equal partitions, a weighted addition of one or more data values of dots contained in one partition, depending upon what percentage of each dot contributes in the partition;
c) replacing the M dots with N dots which have the data values of the N partitions resulting from the weighted additions in step b);
d) repeating steps a) to c) for different sets of M contiguous dots in sequence at least in a part of one horizontal line; and
e) repeating step d) for different horizontal lines in sequence.